[Kinflou]

Records the decisions from 2026-10-20's pass through the smaller open questions.

schema-compatibility.md

• A constant's value change counts by what it reaches (validator/bound → validator rules; field default → patch; otherwise minor).
• Narrowed validation is reported as "validation tightened".
• Unknown enum variants: strict by default, @open opt-in (Unknown(raw) case), no silent fallback; toggling @open is major.
• Forbidding a break: versioning.allow plus build --deny (cli#80). Allowing one needs nothing new (@unverified).
• Builds and releases are separate: builds get pre-release versions; comline release takes the highest computed bump since the last release plus any raise/lower with its reason.
• msgpack@2's keys = name | id parameter.

extensibility.md

• Test vectors and trust: official / third-party with vectors / without (gives up encoding conformance).
• An encoding's package can suggest a default implementation per language; shipping implementations waits for dependency publishing.
• Package-level @unverified: on the encoding's declaration, lowering at release, consumer accept_unverified written by tooling, its own diagnostics family; "not accepted" can't be lowered.

packet-dispatch.md

• Framing instance names can't contain @; a dependency's instances are used by qualified name.
• @consumer is only the counterpart of @provider.

New: proposals/tagged-unions/ (index plus A union declaration, B enum variants with data, C both), under discussion and leaning towards A, so more pros and cons can be gathered.